Japanese researchers claim to have discovered the largest impact crater in the Solar System. This is found on Ganymede, Jupiter's largest moon. The object would have crashed on this satellite at a speed of 20 km/s. It then generated a crater with a radius of 7,800 kilometers!
Ganymede is Jupiter's largest moon. With a diameter 8% larger than the planet Mercury, it is also the largest natural satellite of our entire solar system. However, the two Voyager probes (late 1970s) as well as the Galileo probe (2003) flew over Ganymede and spotted furrows there. As SciTechDaily explains in an August 7, 2020 article, researchers from Kobe University (Japan) claim to have reviewed these hollow formations . Their research will be published in the journal Icarus in December 2020.
Scientists have carried out a precise analysis of the orientation and distribution of the famous furrows over the entire surface of Ganymede. However, it would be the last traces of an impact crater giant ! The directors of the study claim to have been interested in these grooves simply because they are considered to be the oldest surface features of the satellite. In other words, it would be a great way to understand its history.
On Ganymede, the furrows in question are found along a ring pattern. Their radius measures approximately 7,800 km . The researchers performed computer simulations using the "PC Cluster" supercomputer at the National Astronomical Observatory of Japan (NAOJ). These simulations allowed them to affirm that the underlying crater was formed by an asteroid of about 150 km in radius launched at a speed of 20 km/s at the moment of impact. Moreover, this impact would have occurred about four billion years ago.
Thus, Japanese scientists would have discovered the traces of what could well be the largest impact crater of our solar system. It is even four times larger than the Valhalla crater on Callisto (another satellite of Jupiter). The latter counts "only" 1,900 km radius.
For study directors, this discovery may help explain the origin of Ganymede's amazing structure. Indeed, it necessarily required a gigantic supply of heat . However, the impact of the asteroid could very well have been at the origin of this contribution. Either way, the researchers hope that future exploration missions can shed more light. This may indeed confirm their research.
